CVE-2024-45216: Improper Authentication vulnerability in Apache Solr

Should you act?

High exploit likelihood

EPSS ranks it in the top 5% of all CVEs for likely exploitation in the next 30 days. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 92.7%, percentile 99.8: FIRST’s model estimates a 92.7% chance of exploitation activity in the next 30 days, higher than 99.8% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes org.apache.solr:solr (Maven) >= 5.3.0, < 8.11.4, fixed in 8.11.4; org.apache.solr:solr (Maven) >= 9.0.0, < 9.7.0, fixed in 9.7.0. Check your lockfile, including transitive dependencies.

What it is

Improper Authentication vulnerability in Apache Solr. Solr instances using the PKIAuthenticationPlugin, which is enabled by default when Solr Authentication is used, are vulnerable to Authentication bypass. A fake ending at the end of any Solr API URL path, will allow requests to skip Authentication while maintaining the API contract with the original URL Path. This fake ending looks like an unprotected API path, however it is stripped off internally after authentication but before API routing. This issue affects Apache Solr: from 5.3.0 before 8.11.4, from 9.0.0 before 9.7.0. Users are recommended to upgrade to version 9.7.0, or 8.11.4, which fix the issue.

From the GitHub advisory

Solr instances using the PKIAuthenticationPlugin, which is enabled by default when Solr Authentication is used, are vulnerable to Authentication bypass. A fake ending at the end of any Solr API URL path, will allow requests to skip Authentication while maintaining the API contract with the original URL Path. This fake ending looks like an unprotected API path, however it is stripped off internally after authentication but before API routing.

This issue affects Apache Solr: from 5.3.0 before 8.11.4, from 9.0.0 before 9.7.0.

Users are recommended to upgrade to version 9.7.0, or 8.11.4, which fix the issue.

Weakness type: CWE-287, CWE-863.

Product: org.apache.solr:solr (Maven) · Assigned by: apache · Published: 2024-10-16

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 92.75% probability of exploitation activity in the next 30 days; percentile 99.8.

Timeline

• 2024-10-16 — CVE record published by apache
• 2024-10-16 — GitHub-reviewed advisory GHSA-mjvf-4h88-6xm3 published (critical)
• 2024-11-08 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. solr.apache.org solr.apache.org

Vulnerability records

1. GitHub Advisory GHSA-mjvf-4h88-6xm3 github.com
2. CVE.org record CVE-2024-45216 cve.org
3. NVD entry CVE-2024-45216 nvd.nist.gov

Other references from the CVE record and advisory

1. openwall.com openwall.com
2. issues.apache.org issues.apache.org

Critical Maven advisories · Today’s Security Digest